1. Cross Reference to Related Applications
This application is related to U.S. patent application Ser. No. 08/120,720, "Expansion Chassis For A Voltage Regulator Controller", filed on Sept. 13, 993; and U.S. patent application Ser. No. 8/101,133, "Removable Field Programmable Data Memory Module" filed on Aug. 2, 1993, now U.S. Pat. No. 5,455,505, both of which are incorporated herein by reference in their entireties.
2. Field of the Invention
This invention relates to line actuators and related control electrical apparatus, such as circuit protection and control devices, for electrical power distribution system apparatus.
Line control apparatus or systems may take a variety of forms. For example, one type of line control system, a step-type voltage regulator, is used to maintain a relatively constant voltage level in a power distribution system. Without such a regulator, the voltage level of the power distribution system could fluctuate significantly and cause damage to electrically powered equipment. Another common type of line control electrical apparatus is a circuit breaker or interrupter. Circuit protection devices typically detect when an undesirable condition, such as a ground fault or overcurrent, occurs on the line and disconnect power to loads on the protected line when the condition is detected.
Line control systems that handle larger loads often include two distinct parts: an actuator (such as a step-transformer or circuit breaker mechanism) and a controller (such as a voltage regulator controller, trip unit, or protective relay). The actuator includes the mechanism or other means by which the line voltage and/or current is varied (e.g. turned off, or stepped up and down). The controller includes logic (such as a microprocessor and control program) that determines how and when the line voltage is to be varied by the actuator.
In order for the actuator and the controller to work together to maintain the proper line characteristics, the controller is commonly provided with the specifications of the actuator. For example, information such as the actuator's voltage rating, current rating, configuration and impedance characteristics may be programmed into the controller. In voltage regulation systems, information such as number of tap changes and temperature extremes may also be maintained by the controller so that a field engineer can determine when to change or service the voltage regulator.
The problem with maintaining such information at the controller is that each time a new controller or actuator is put in place, the controller may need to be reprogrammed by the field engineer. This process can be time consuming and prone to entry errors. When the actuator is changed, information is typically read from the data plate or manual and parameters are keyed into the controller by hand. In cases where the controller is changed, historical data concerning the actuator are commonly re-keyed or transferred from one controller to another.